The present invention relates a method for determining an uneven surface height and a depression/protrusion of a pattern on a sample or obtaining three-dimensional information, and more specifically to a method suitable for obtaining information of depression/protrusion of a line and space pattern formed on a semiconductor wafer and an apparatus therefor.
Charged particle beam apparatuses, such as a scanning electron microscope, are apparatuses suitable for measuring and observing a pattern formed on a semiconductor wafer that is developing toward further microfabrication. Conventionally, there is a stereoscopic observation method as disclosed in JP-A-5-41195 as a method for obtaining three-dimensional information on a sample with a charged particle beam apparatus.
The stereoscopic observation method obtains three-dimensional information by taking two oblique stereoscopic images, conducting stereoscopic matching between the two images to find corresponding points, and calculating the heights.
And, JP-A-5-175496 discloses a technology that irradiates a beam obliquely onto a pattern on a sample to measure the dimensions of the pattern.
Further, U.S. Pat. No. 6,872,943 B2 discloses a method for determining a depression/protrusion of a pattern by irradiating a beam obliquely.